Leonardo da Vinci’s 1480s vertical-flight design with a helical rotor is called the aerial screw.
Leonardo sketched the machine around 1489. Its large spiral-shaped sail was intended to screw upward through the air when four people turned cranks connected to the central shaft. The design is often described as an early helicopter concept, although it could not have flown as drawn because the proposed human power was insufficient.
The aerial screw was inspired partly by Leonardo’s observations of seeds and airborne structures. Its linen-covered helical surface resembles a giant screw rather than the powered rotors used by modern helicopters. Leonardo did not build a documented working version.
A common mistake is to call it the first helicopter. It was a Renaissance design for vertical flight, not a functioning aircraft, and its mechanism differs substantially from a modern helicopter’s rotor system. The sketch remains one of Leonardo’s best-known studies of flight and engineering.